The ATLAS3D project - II. Morphologies, kinemetric features and alignment between photometric and kinematic axes of early-type galaxies

摘要: We use the ATLAS3D sample of 260 early-type galaxies to study apparent kinematic misalignment angle, Ψ, defined as angle between photometric and major axes. find that 71 per cent nearby are strictly aligned systems (Ψ≤ 5°), an additional 14 have 5° <Ψ≤ 10° 90 Ψ≤ 15°. Taking into account measurement uncertainties, can be considered better than 5°, suggesting only a small fraction (˜10 cent) not consistent with axisymmetry within projected half-light radius. identify morphological features such bars rings (30 cent), dust structures (16 blue nuclear colours (6 evidence interactions (8 visible on galaxies. KINEMETRY analyse mean velocity maps separate two broad types regular non-regular rotators. 82 rotators 17 rotators, we were able classify due poor data quality. The typically found in dense regions massive. characterize specific dispersion maps. majority do any features, but highlight here frequency kinematically distinct cores (7 galaxies) double peaks (4 galaxies). five groups based kinemetric which then used interpret (Ψ-ɛ) diagram. Most misaligned complex kinematics In addition, some show interaction might equilibrium, while barred. While trends weak, there is tendency large values Ψ at intermediate environmental densities among most massive sample. alignment analysis, more similar spiral discs remnants equal-mass mergers. suggest common formation mechanism for preserves disc progenitors their general properties. Less commonly, process results triaxial galaxy much lower net angular momentum.